The present invention relates in particular to a microfluidic flow device. Conventionally, such a microfluidic flow device comprises at least one microchannel, for the flow of at least one fluid.
The characteristic dimension of each microchannel, as intended by the invention, is comprised between a few microns and 1 millimeter. Typically, this dimension causes a substantially laminar flow in the microchannel, with a Reynolds number lower than 1.
A microfluidic flow device is known from the article “Quantitative analysis of molecular interaction in a microfluidic channel: The T-sensor” (anal. Chem. 1999, 71, 5340-5347) which is referred to below as Yager et al. This flow device comprises two upstream channels, and a single downstream channel, which define a T shape. This publication describes the possibility of making a target fluid, and also a fluorescent indicator, flow in the downstream channel, in order to determine the concentration of this target fluid by measuring the fluorescence in a region of this channel, where interdiffusion occurs between the target fluid and the indicator.
Microfluidic techniques are used to provide access simply and/or rapidly and/or very accurately to chemical or physicochemical data. These techniques use fluid flows in channels. The fluids investigated are generally mixtures of chemical or biological compounds whereof the properties are analyzed at one or more points of the channel. The chemical or physicochemical history of the fluid evolves during their advance in the channels, by simple changes in a mixture (reaction kinetics, crystallization kinetics etc.) over time, and/or by mixing of several materials in the device. This makes it possible to perform analyses, investigate chemical or physicochemical or biological reaction mechanisms, design new materials at a small scale and investigate their properties, or even produce compounds.
To conduct these operations, fluid streams can be handled in channels. For example, a stream can be divided into two streams which each undergo a different treatment and/or different analyses. Two streams can be combined to create or investigate reactions.
Microfluidic devices are known comprising branch points (or junctions) and in which flows are conducted.
Plug flows (or “drops” or “plugs”) are known in carrier fluids, like those described in WO2004038363, and devices for implementing such flows.
A need exists to improve the handling of the streams in microfluidic devices. A need exists in particular to improve the handling of plug streams, for example to distribute them better in various channels, and/or to merge various plugs thereby creating reaction mixtures, and/or to arrange and sort families of plugs and/or to ensure that they reach the destinations in the channels for which they are intended.
In particular, in general, a constant need exists in the industry to develop new products, having new properties, for example new chemical compounds or new compositions comprising new chemicals and/or new combinations thereof. The physical and/or chemical conversions of the products are important properties for many applications, which very often should be tested in Research and Development processes. A need exists for methods and installations for accelerating the Research and Development processes, for example to test a larger number of products and/or to conduct the tests on smaller quantities of products, and/or to conduct the tests more rapidly.